Base for swivel chairs



y July 17, 1951 T. ELLEMAN BASE FOR SWIVEL CHAIRS Filed Dec. 23, 1944 INVENTOR. TOM ZLE/Izw a MJ Patented July 17, 1951 UN IfTED-f fSrfTAi E45 O-FFHCE BASE FOR-'SWIVEL CHAIRS;

Application December 23, 1944, Serial-No.'569,522#` 2Qlaims. ,l (Cl. 248-194) This invention relates to an improvement: in bases for swivel chairs, particularly to?. thelhub which holds the, legs. of the base` together and provides the supportfor the chair ironspindle.

OneA of the yobjects of-this invention is to provide a hub` which grips the wooden legs with a continual pressure even whenchanges occur. in their thickness, andalsoprovides a bearing for the spindle which will permit the spindle to rotate .readily and withstand wear.

Another objectof the, invention isV to provide ahub in which the spindle isvertically adjust' able bynieans. requiring a minimumfamount-of space ybetween thechairspider and thetop of the hub.

These objects are obtainedby forming thehub from, legbrackets.made from. steel stampings held in ,semi-flexible relationship. to a, cast. iron sleeve ortube and supportingthechair ironspindlewithinthecast iron` sleeve. The; cast iron thespindle even when lubrication is notpresent,

asthe surfacecharacteristics oLcast iron,.vpr ob ably duetolits `highjcarloon content, aresuch as, toreducefriction toa-.minimum and increase-fthex However, tofmakeV life of the hub and spindle. thehubcompletelyvof cast iron would unduly increase weight and not provide the advantages arising from thefusegoffleg brackets formed of steel stampings. These leg brackets which are secured tov the cast ironv sleeveiin-vsuch Vaway as to permit them to ex along most of their legengaging portionprovidef. a .continuous holding pressureeven though the thickness of the woodenlegmay. alterdue to manufacturing errorsand differencesin climatic conditions to which the wood is,subjected. The necessary-space between the. chairT iron mounted onthe spindle andfthe top -of the hub required for the adjusting hand wheel iskeptto a minimum by providing a-flange on vtheetop, plate of the hub, a hand wheelwh-ich has aI downwardly depending flange enclosing the la-ngeon the hub, a keyv washer between the hand wheel. and the top of the hub, and :a screw inthe downwardly depending. flange totunder the flange on the hub. This lessening ofthe requiredzdistance between the chair iron and the top of the hub makes it possible to provide a hand wheel which has a greaterlength ofrthread and also permits an additional lowering of the chair seat relative to the base.

With the foregoing and other objects in view, developed by the following description, the invention consists in certain novel advantageous structural organizations and features, as well as 2 confibinations. and.l sub-combinations as more4 fullyv explained`r hereinafter and specied in the following. claims., A

Referring to the accompanying, drawing. formingv a part hereof, Figure 1r is` a fragmentary view partlyinsideelevation andpartly in -vertical secti0n,of, a chairhub sembodying.` the. -present invention, part,of, oneL of. theflegs. being broken away forl thesakeof clarity inillustration;

Figure 2 ,is a viewtaken on .the line 2,-2 of Figure 1 withthehand wheel.,removed for, the sake of.- clarityl l in disclosure;

FigureL 3 isa fragmentary.. sectional view taken on xthe line. 3730i. Figure` 1;

Figure, ,4 isfa fragmentarysectional -view taken onthe ,line.,4.-4- of, Figure; and h Eigurev is abottom plan view of the hubfviewed in Eigurelwith. thelegs and .handwheel removed and with a part. broken awayforv the purpose of clarity in illustration.,

Referring; ingreater detail.to the drawings, there is.shownr..ahubl for thebase of swivel chairs, designated. as arwhole at l. It is secured to the W0oden,leg s.2..of thevchair:l base as hereinafter described; Thehub I. rotatably supports the spindle of the-chair, iron. Tothis spindle is securedithe chair, iron. (notY shown) for holding the` chair. seat.v Thehub l asa whole comprises two mainlparts: the supporting orhub-portion per. se.; ,and thehand .wheeler vertical adjusting means. The. hub per. se comprisesa-central cast iron ,r.sl,eevey or tube (iA andleg. engaging brackets-9. The cast. iron1sleevet-.has-atitsupper end an outwardly.v extending ange I0 which formsthe bearing for the vertical thrust imposed by the spindle Stand .the support for the top l,plate 1. Adjacent .the bottom .ofthe sleevef there is another outwardly` extending ange I I. which forms a shoulder for. the `washerfa.

The top, plate- 'I has a central, aperture into which the. top portion ofthe sleeve 6. is pressfittedy to. form a. tight juncture therebetween. The top plate 'l has .an upwardly and outwardly curved iiangeV I2. providing one of the abutting means between the hub and the hand Wheel to prevent `'separation .while :permitting relative rotation therebetween. Thetop plate Thas equally angularlyspaced` screwy receiving aperturesv whereloyit'mayQ be securely-fastened to the woodcnlegs 2., The legbracketsopside pieces 9 are each of similar construction and are somewhat U-shaped in cross section. At the spaced intervals along each leg bracket there are provided ribs or bosses lli pressed outwardly therefrom to stiften and strengthen the arms of the bracket.

The leg brackets are positioned at four equallyspaced angular places about the tube 6 and the legs 2 are received between the opposing side arms of adjacent leg brackets. Fish-tail lugs l are provided at the top of each arm of the leg brackets 9. They t through rectangularlyshaped openings provided in the top plate as is shown in Figure 2 and are spread as illustrated to form a rigid connection between the brackets and the top plate. Slots 9a are provided in the central portion of the bottoms of the brackets 9 to receive radially-extending Wings or ears `|3 formed on the washer 8b. After the leg brackets 9 have been secured to the top plate 1, a washer 8a is press-tted over the bottom of the tube 6 and ts snugly against the shoulder formed by the lower flange Il. This washer is provided with four flat portions which engage with the lower central portion oteach leg bracket 9 to properly position those flanges and hold them from moving inwardly toward the sleeve 6. Thereupon, a washer 8b provided with radiallyextending wings or ears I3 is press fitted on the lower end of the tube 6 with the wings extending in the slots 9a. The ends of the wings I3 are then formed upwardly as shown in Figure 1 to grip and hold the bottoms of the leg brackets securely in place with respect to the sleeve 6.

This method of securing the leg brackets provides for a rigid attachment relative to the sleeve 6 but permits relative movement between the lower portions of the side arms of the leg brackets, thus making those arms free to ex throughout a substantial portion oftheir length. As the legs 2 are forced in between the side arms of the leg brackets, they will elastically deform these brackets and cause them to be placed under stress thereby forming a continuous pressure between the leg brackets and each leg, even though the thickness of the legs subsequently changes as the result of partial drying due to climatic conditions. The stress imposed upon the brackets during the assembly process will be sufficient to maintain such continuous pressure even when changes in thicknesses of leg thereafter occur. Because of the flexibility of the leg brackets, slight variances in the thicknesses of the legs used in the assembly of the chair base will not cause manufacturing diiculties. The flex will give suiciently to accommodate oversize legs. As an added protection in maintaining the legs rigidly in place, screws 16a may be inserted through the openings I6 into the wooden legs 2.

The spindle 3 is rotatably held within the central longitudinal aperture in the cast iron sleeve 6 and is guided thereby. In order to permit adjustment of the spindle 3 vertically relative to the sleeve 6, the spindle is provided with a standard thread upon which is threaded a nut or hand wheel 20. The hand wheel 20 has a central hub 2| and a downwardly-extending ange 2l which extends over the upwardly and outwardly-extending iiange l2 of the top plate 1. The bottom of the hub 2| is provided with radially-extending depressions 26. A key washer 22 has similarly-shaped projections which coincide with and t into the depressions 26 to prevent the Wheel 20 from turning with respect to the washer 22 unless additional turning pressure is manually exerted on the hand wheel l2|). The key washer 22 has a tab 23 which rides in a key Way 24 extending vertically through the threaded portion of the spindle 3. This causes the key washer to be fixed against relative rotation with respect to spindle 3. Thus the thrust placed on the spindle 3 is transferred through the hub 2| and key washer 22 to the top of the cast iron sleeve 6. As the chair iron is swivelled, the spindle 3, key washer 22, and hand wheel 20 are rotated together, and no vertical adjustment is attained. When the weight of the occupant of the chair seat is removed, the hand wheel 20 may be manually rotated with respect to the spindle 3, thus raising or lowering it with respect to the spindle 3 to adjust the height of the chair seat.

Although only one embodiment of the invention is shown and described herein, it will be understood that this application is intended to cover such changes or` modications as come within the spirit of the invention or scope of the following claims.

I claim:

1. A hub for a chair base comprising: a cast iron sleeve adapted to receive and rotatably support a chair iron spindle, said sleeve having a flange at its upper end and a at bottomed shoulder adjacent its lower end; a top plate abutting the underside of said flange and having a press fit on said sleeve; stamped sheet metal leg brackets having upright leg engaging side arms secured to said top plate to anchor said brackets; and means secured to the sleeve in abutting relationship to the flat bottom of said shoulder to secure the lowery ends of the leg brackets in spaced relation tothe sleeve while leaving the leg engaging side arms free to ex.

2. A hub according to claim 1 wherein the means to secure the lower ends of the leg brackets comprises a spacing washer abutting the shoulder and engaged with the leg brackets to hold them spaced from the sleeve, and a securing washer press tted on the sleeve in abutting relationship to the spacing washer, said securing washer having ears engaging the bottoms of the leg brackets to hold them inwardly against the spacing washer.

TOM ELLEMAN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 173,772 Davis Feb. 22, 1876 714,764 Watkins Dec. 2, 1902 1,182,889 Bolens May 16, 1916 1,422,933 Dawson July 18, 1922 1,459,138 Bolens June 19, 1923 1,484,371 Brown Feb. 19, 1924 1,501,180 Peters et al. July 15, 1924 1,570,437 Dawson Jan. 19, 1926 1,709,446 Travers Apr. 16, 1929 1,717,142 Bump June 11, 1929 1,872,894 Collier et al. Aug. 23, 1932 2,168,810 Sheldrick Aug. 8, 1939 2,251,841 Herold Aug. 5, 1941 2,356,507 Cramer Aug. 22, 1944 2,430,043 Bolens Nov. 4, 1947 

